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authorJason A. Donenfeld <Jason@zx2c4.com>2022-11-06 16:02:43 +0100
committerJason A. Donenfeld <Jason@zx2c4.com>2022-11-18 02:18:10 +0100
commitdb516da95ce458f0cab5e7ae2db93fd821484d7d (patch)
tree7025999d032360dfcd0f5dc4c772f5206dff0fd0 /drivers/char/hw_random
parent19258d05b619d26622bdcfa11eca1f457b69e4da (diff)
downloadlinux-db516da95ce458f0cab5e7ae2db93fd821484d7d.tar.bz2
hw_random: use add_hwgenerator_randomness() for early entropy
Rather than calling add_device_randomness(), the add_early_randomness() function should use add_hwgenerator_randomness(), so that the early entropy can be potentially credited, which allows for the RNG to initialize earlier without having to wait for the kthread to come up. This requires some minor API refactoring, by adding a `sleep_after` parameter to add_hwgenerator_randomness(), so that we don't hit a blocking sleep from add_early_randomness(). Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Diffstat (limited to 'drivers/char/hw_random')
-rw-r--r--drivers/char/hw_random/core.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c
index cc002b0c2f0c..63a0a8e4505d 100644
--- a/drivers/char/hw_random/core.c
+++ b/drivers/char/hw_random/core.c
@@ -69,8 +69,10 @@ static void add_early_randomness(struct hwrng *rng)
mutex_lock(&reading_mutex);
bytes_read = rng_get_data(rng, rng_fillbuf, 32, 0);
mutex_unlock(&reading_mutex);
- if (bytes_read > 0)
- add_device_randomness(rng_fillbuf, bytes_read);
+ if (bytes_read > 0) {
+ size_t entropy = bytes_read * 8 * rng->quality / 1024;
+ add_hwgenerator_randomness(rng_fillbuf, bytes_read, entropy, false);
+ }
}
static inline void cleanup_rng(struct kref *kref)
@@ -528,7 +530,7 @@ static int hwrng_fillfn(void *unused)
/* Outside lock, sure, but y'know: randomness. */
add_hwgenerator_randomness((void *)rng_fillbuf, rc,
- entropy >> 10);
+ entropy >> 10, true);
}
hwrng_fill = NULL;
return 0;